package cn.edu.scau.cmi.shishuai.exercise4;

public class Circle {
	double radius,area;
	Circle(){
		
	}
	Circle(double r){
		radius = r;
	}
	void setRadius(double r) {
		if(r>0) {
			radius = r;
		}
	}
	double getRadius() {
		return radius;
	}
	double getArea() {
		area = 3.14*radius*radius;
		return area;
	}

}
